Some known extracorporeal blood treatment devices, such as hemodialysis machines, draw blood from a patient via a blood circuit, circulate the blood through a treatment unit of the blood circuit, and then return the treated blood to the patient via the blood circuit. This circulation of the blood outside the patient's body typically begins and ends with the passage of the blood through a single or dual lumen catheter system that is connected to the patient. The circulation of blood is generally assisted by a pump to increase the rate of blood flow, as well as to provide a regulated flow of blood throughout the treatment.
Sometimes a degradation in blood flow may occur, which may compromise treatment efficacy. Such blood flow degradation can be the result of an access blockage, such as a needle of the catheter system contacting a wall of a vein in which it is inserted and thereby inhibiting blood flow. Other blood flow degradation can result from a kinking or binding of blood circuit tubing and/or the formation of a clot. Clots may occur, for example, at an access point (i.e., a point at which the blood circuit connects to the patient) or within the blood circuit, such as at an input of the treatment unit.